Sewing machine



Jan. 25, 1944. w. SIMPsN 2,339,887

SEWING MACHINE Filed Jan. 18, 1940 2 S11ee:.s-S11eef.- l

FIC. I` FIG. 2

Jan. 25,1944. w, slMPsQN 2,339,887

SEWING MACHINE Filed Jan. 18, 1940 zs'heets-sheet 2 Will/[11111]# Patented Jan. 25, 1944 assist? SEWING MACHINE William Simpson, irmingham, England, assigner to Newey Brothers.Limited,Birmingham, Eng-.-

land.

i Application January 18,1940, serial No.- eigs'm' vIn Great-Britain May'lfi; 1939 7 Claims; (cLiiz-f-m i The invention relates to means ior'protecting the needles of sewing machines when tapes or bands of metal iastenings, more especially eye tapes, are being stitched to garments or other articles'.

Devices for preventing the needle of a sewing machine from encountering the wire of the fastening devices in such circumstances have hitherto operated -by causing a slight displacement of the eye or the like when it happens that the stitching stroke of the needle would otherwise bring the needle onto the'wire of the eye.

For example an oscillating finger operated by the machine is timed to reach the stitching position in advance of the needle and, by means of reaction surfaces on it, will force the wire forwardly or rearwardly as rit descends, according to the part of the circular section wire engaged by its tip.

The object of the invention is to provide a simple and eiective means which will not move or displace the eyes on the tape or band, but will move the needle relative to its normal stitching path each time a wire of an eye on the tape crosses the stitching point.

The means according to the invention is particularly suitable for attachment to sewing machines of the kind in which the needle moves in a curved path for assisting in the feeding of the material which is being stitched. In this kind of machine the needle is mounted by a holder on a needle bar mounted to slide in bearings in a rock frame pivoted in the head of the main arm casting.

In its broadest aspect the invention consists in the combination of a needle bar permitted a degree of horizontal movement in relation to its actuating means, a spring arranged toresist this movement, a trip iinger which rests lightly on the work and can ride up on the wires of the fastenings when these cross the stitching point, and a bolt or catching device which is operated from the linger, when the latter is raised, and which engages the needle bar in order to cause the needle to descend in a position diierent with respect to the normal stroke so that it will miss the wire.

In accordance with the invention when 'applied to machines of the kind for which it is particularly suitable I allow for a small rocking movement between the needle bar rock frame and its driving connection with the rock shaft and prevent this movementunder normal stitch-f ing conditions by arranging a spring to resist it. I then provide a bolt or latching appliance.

worked bya pilot -nger or feeler under which the Work is' fed and arrange thev finger or ieeler sothat when it-encounters awirel of an eye or like fastening, it rides up on it, which movement causes the boltor latch to engage the needle bar and against the force of the spring to restrain its rocking' movement, thereby displacing the needle from the line of its normal down stroke and causing it to come down in a position where it will miss the object but whence it can clear the object in its next normal stroke when the work has been fed along.

A preferred arrangement of the pilot finger and thelatch or bolt is to clip a depending,

bracket on a -fn'ied part, for example a presser bar bushing, and vto mount a bell crank lever on this bracket with the nger adjustably secured to one arm and ther other arm slidably connected to a radius arm hinged on the bracket which arm'carries a catchr or bolt, preferably a springpressed bolt, at its' outer end.

The bolt locks a faced block secured on a part having a xed relationV to the needle in its rocking motiongbut `free from it in its up and down motion.- A convenient attachment for this block is on the lower extremity of the rock frame in which the needle bar 'is reciprocated. If the bolt is spring-pressed, itl-may engage the block without damage if it should be raised by the nger and bell crank before the block on the rock frame has swung back vfar enough for the bolt to pass in front'o'f it. y

Iprefer to provide a thin guard piece closely adjacent the pilot finger tip to protect it from the thrust of the work as the latter is pushed into the machine by the operator and to keep the work level inthe neighborhood of the nger. This guardpieceimay easily be carried by the tape guide 'or by a small post secured to the removable plate on the work table of the machine.

AThe appended drawings illustrate one con-` venientembodiment of the invention applied to a Singer two needle high speed compound feed machine.-

^ Figure 1A is an end elevational view looking at the head of the machine with the face plate removed and with thel attachment in place.A

Figure 2 is a side elevation of the head with thefront wall broken away.

Figuresv 3, 4 and 5 are transverse sectional views of the machine showing different working positionsof the-parts to illustrate the operation of the device, the mechanism being viewed in a directionl opposite to that in Figure l.

Figure 6 is a plan of the throat plate and feed dog.

Figure 7 is a view of a small face portion of the needle bar rock frame slide looking in the direction of the arrow 'I in Figure 2, showing the lost motion provided between it and its slide way in the rock frame.

Figure 8 is a viewof the guard piece.

Figure 9 shows the catch block attachment in perspective.

In the drawings a is part of the arm casting of the machine carrying the work head b at its extremity. c is the presser bar in the head b and d is the lower bushing through which this bar is moved by a hand lever to raise and-lower the presser foot e which is secured to the bottom of the bar. The needles are marked f, the needle holder g, and the needle bar h. The upper and lower guides for the needle bar h in the needle bar rock frame z' are marked :i and lc respectively. The rock frame i swings on a pivot m in the topof the head under the stroke of a slide block n mounted on the cranked end oof the rock shaft p. 'I'he connecting stud q clipped on the bar h is mounted in the connecting link or rod r on a crank on the arm shaft (not shown) of the machine, to drive the needle bar up and down as it is rocked forwardly. and baokwardly by the rock shaft.

The slide block n engages and is ordinarily a working t in a slideway t on the guide 1c of the rock frameV z', so that the needle bar is positively rocked as it is raised and lowered and the needle is vthus given an elliptical movement in a vertical plane in an opposite direction to that imparted to the feed dog u and between these motions the work is fed as it is stitched.

Figure 'l shows at v a space between the slide block n and the sides of its slideway t which is allowed for the purpose of the invention. This might be varied to suit different thicknesses of the wire, and the blocks could readily be arranged to be interchanged. It hasbeen found that a 115 is' sufficient for standard Wire eyes of` 42 gauge and stitching upto sixteen to the inch. u

w is a screw clip forming part of a bearing bracket in the bearing y of which the pivot a' of aubell crank lever is mounted. This clip W is `clamped on the bottom guide bushing d of th the presser bar c. Acompression spring I I located between a guide projection (such as a small screwhead) on the clip w and a similar pro jection on a second screw clip I2, which carries a machined catch block I3 and which is clamped on the bottomof the needle fbar rock frame, keeps the rock frame up against: the block n on the drive crank o of the rock shaft p.

y The short arm I4 of the bell crank pivoted at e hasadjustably secured within a grooved seating on one face (see Figure 1) a finger I5 with a pointed hook-like tip IB. `The hook tip rI6 is abrupt on one side butrounded or inclined on its forward edge so that it will rise as the wire I1 of an eye on a piece of tape encounters the nger I5, see Figure 3. The longer arm I8 of the bell crank carries a small block I9 at its end which slides in a slot 20 in a radius arm 2| pivoted on the bracket a: at 22, and-so swings that arm upwardly when the finger I is tripped, so that it can come in front of the machined, smoothvface of the catch block I3 projecting from the jaw clip I2. The front face of the `catch block' I3 and. the rear face of the catch bolt 23 are complementarily inclinedto facilitate engagement and retention of engagement. A light spring 24 returns the bell crank when the obstruction that caused the lifting of the nger and the catch bolt 23 has passed the stitching point; the spring insures a quick return so that stitching between adjacent wires of an eye may take place in proper manner.

Aguard yblade 26 lies adjacent to the nger I5 for the purposes mentioned earlier in the more general parts of this specification. The blade isf carried by an arm 21 having an attachment block 28 by which it can be screwed to a re- `movable slide plate on the machine.

It has been found convenient to remove part of the feed'dog u and to use a throat plate 29 which has a plane portion 30 Where this feed dog part is removed, broken only by a slot 3| allowing for the needle movement. This smooth plane forms a convenient surface over which the finger I5 may operate on the work passing over thejsurface. I 4

-The operation of the device will be fairly clear from what has already been' said about its con# struction. In the drawings in Figure 1 the needle and the pilot finger are shown in the ordinary stitching position of the machine the needle beingin the act of making its down stroke into the material. In Figure 3 the position is shown in which a wire I is encountered by the tip I6 of the nger and the bolt catch 23 has been brought up into engagement with the catch block I3 so that the needle as it makes its down stroke cannot come down in its normal -position in relation to the feed dog u but is descending a small distance (actually 1%") to the rear of this position that is to the right in the figure. In Figure4 the needle is shown ascending and the nger I5 has ridden off the Wire I l. The feed dog is in process of descending having carried the material along towards the back of the machine, that is the right of the figure. In Figure 5 the position is approximately the same as in Figure 3 with thefeed dog and needle approaching each other, but as there is no wire tipping the nger I5,'the parts are inthe normal relationship for a stitching stroke. Therefore the needle isrdirected more towards the front of the slot in the feed dog u than is the case in Figure 3.

I claim:

1. In a sewing machine for stitching materiall in which wire obstructions are encountered, the combination of a pivoted rock frame, a needle bar having a needle supported in said frame for vertical reciprocation andv for lateral vibrating movementl with said frame in a plane of feed movement of the material, means for rocking said frame normally to impart lateral Vibration to thevneedle of a constant amplitude, said means including a spring for causing said rock frame to maintain its normal amplitude of vibration-in one direction, and means engageable with. an obstruction in the normal path of reciprocatory movement of the needle andoperative to restrain the frame against its full range of movement by the spring for movement of the needle through the material to one side of the obstruction.-

2. In a sewing machine for stitching material in which wire obstructions are encountered, the combination of a pivoted rock frame, a'needle bar slidably mounted in said rock frame for ver-f tical reciprocation, driving means for saidrock frame, said driving means including a lost m01 tion connection interposed between said driving means and said rock frame, a spring normally resisting lost motion in said connection, a pilot nger riding on the surface of the work, and means operated by said pilot nger upon engagement with an obstruction to overcome the action of said spring to permit lost motion in said connection.

3. In a sewing machine for stitching material in which wire obstructions are encountered, the combination of a pivoted rock frame, means for driving said rock frame, a needle bar mounted for vertical reciprocation in said rock frame, a lost motion connection between said rock frame, and said driving means, a spring resisting lost motion in said connection, a pilot ringer riding on the surface of the work, and means operated by said pilot finger to overcome the action of said spring whereby lost motion in said connection is established and said rock frame is prevented from completing a rocking movement of normal amplitude.

4. In a sewing machine for stitching material in which wire obstructions are encountered, the combination of a pivoted rock frame, means for driving said rock frame, a needle bar mounted for vertical reciprocation in said rock frame, a lost motion connection interposed between said rock frame and said driving means, a spring resisting lost motion in said connection, a pilot finger riding on the surface of the work, and means operated by said pilot nger to overcome the action of said spring to establish lost motion in said connection, said means withholding said needle bar and said rock frame from the normal rocking movement when said pilot iinger encounters an obstruction in the work during the downstroke of said needle bar.

5. In a sewing machine for stitching material in which wire obstructions are encountered, the combination of a needle bar mounted for vertical reciprocation and lateral vibration, a needle holder mounted on said needle bar, and means for withholding said needle bar from its normal lateral vibration when an obstruction crosses the normal stitching point during the downstroke of said needle bar.

6. In a sewing machine for stitching material in which wire obstructions are encountered, the combination of a rock frame, a needle bar mounted in said rock frame for vertical reciprocation and lateral Vibration, a catch for restricting the lateral vibration, and a pilot linger riding on the surface of the work, said pilot finger actuating said catch when an obstruction in the work is encountered.

'7. An attachment for a sewing machine comprising a clip to be secured to a fixed part on the machine, a bracket depending from said clip and carrying a bearing for a bell crank lever, one arm of said bell crank lever mounting an adjustable pilot nger, the other arm of said bell crank lever mounting a sliding connection with a radius arm pivoted on said bracket, a needle bar rock frame, means actuating said needle bar rock frame, means for connecting said needle bar rock frame to said actuating means, said connecting means permitting movement of said needle bar rock frame with respect to said actuating means, a latch bolt on said radius arm adapted to engage a catch on the needle bar rock frame when said pilot finger actuates said radius arm through said bell crank lever.

WILLIAM SIMPSON. 

